Wash and paper towel pat dry your veggies. Into a large bowl, thinly shred 1 green cabbage onto benriner mandolin (adjust to 1-2mm thickness). Insert coarse blade into the mandolin and slice 1 English cucumber into the bowl with cabbage (remove coarse blade once done). Cut 1 orange bell pepper and 1 red bell pepper into 8 wedges, remove the seeds and slice onto the mandolin. Finely chop 1 bunch green onions and 1 bunch dill; add the herbs to the salad.
To Make the Dressing: In a small bowl, combine and whisk 1/2 cup grapeseed oil, 1/4 cup distilled white vinegar, 1 tbsp sugar and 1 tsp fine salt. Let it sit for 5-10 mins in order for sugar and salt to dissolve a bit. Pour the dressing over the salad and give the salad a good stir in order for dressing to fully cover all the veggies. Refrigerate salad for at least 2 hours before serving. Stir, taste and add salt if necessary before serving.